Solar cell and preparation method thereof, electric equipment and power generation equipment

Abstract

The invention provides a solar cell and a preparation method thereof, electric equipment and power generation equipment. The preparation method comprises the following steps: forming a first charge transport layer on one side of a substrate; a mixed layer is formed on the side, away from the substrate, of the first charge transport layer through evaporation, and the mixed layer comprises perovskite inorganic salt and a pore forming agent; forming a perovskite organic layer on the surface, far away from the substrate, of the mixed layer, wherein the perovskite organic layer comprises perovskite organic salt; performing first heat treatment on the mixed layer and the perovskite organic layer, and removing the pore-forming agent; and performing second heat treatment on the mixed layer and the perovskite organic layer, and reacting the perovskite inorganic salt with the perovskite organic salt to obtain the perovskite light absorption layer. The pore-forming agent is removed in the first heat treatment process, and then pores are formed in the perovskite inorganic layer, and in the second heat treatment process, the pores can enlarge the reaction area of the perovskite organic salt and the perovskite inorganic salt, improve the reaction efficiency between the perovskite organic salt and the perovskite inorganic salt, and improve the reaction sufficiency between solid phases.

Description

Technical Field

[0001] The present invention relates to the field of battery technology, and in particular to a solar cell and a preparation method thereof, an electrical device and a power generation device. Background Art

[0002] Perovskite solar cells have attracted extensive research due to their excellent photovoltaic performance and low cost. In perovskite solar cells, the perovskite light-absorbing layer can be prepared by solution method and evaporation method, and its quality directly determines the performance of the cell. Among them, the evaporation method is more advantageous in the application of large-area cells. The evaporation method can be divided into a one-step co-evaporation method and a sequential evaporation method, that is, the inorganic salts and organic salts in the perovskite components are evaporated separately. The sequential evaporation method can better adjust the component ratio. However, since the evaporated perovskite components are all solid phases, the reaction between the solid phases is difficult to be complete, which becomes a major problem of the sequential evaporation method. Summary of the invention

[0003] The present invention aims to solve one of the technical problems in the related art at least to a certain extent. To this end, one object of the present invention is to provide a method for preparing a solar cell, which can effectively improve the reaction efficiency between solid phases.

[0004] In one aspect of the present invention, the present invention provides a method for preparing a solar cell. According to an embodiment of the present invention, the method for preparing a solar cell includes: forming a first charge transport layer on one side of a substrate; evaporating a mixed layer on the side of the first charge transport layer away from the substrate, the mixed layer including a perovskite inorganic salt and a pore-forming agent; forming a perovskite organic layer on the surface of the mixed layer away from the substrate, the perovskite organic layer including the perovskite organic salt; performing a first heat treatment on the mixed layer and the perovskite organic layer to remove the pore-forming agent; performing a second heat treatment on the mixed layer and the perovskite organic layer, and the perovskite inorganic salt and the perovskite organic salt react to obtain a perovskite light-absorbing layer. In the preparation process, a pore former is mixed into the evaporated perovskite inorganic salt, and the pore former is removed in the first heat treatment, thereby forming pores in the perovskite inorganic layer. During the second heat treatment, the pores can increase the reaction area of ​​the perovskite organic salt and the perovskite inorganic salt, or in other words, increase the reaction space, thereby improving the reaction efficiency between the perovskite organic salt and the perovskite inorganic salt, and improving the sufficiency of the reaction between the solid phases, which helps to improve the energy conversion efficiency of solar cells.

[0005] According to an embodiment of the present invention, the pore former includes an organic amine compound.

[0006] According to an embodiment of the present invention, the pore former includes at least one of semicarbazide, allyl urea, tetramethyl urea or n-butyl urea.

[0007] According to an embodiment of the present invention, the first heat treatment method comprises: heating at 60-100° C. for 30-60 min in a vacuum environment, with a vacuum value less than or equal to 3×10 -4 Pa.

[0008] According to an embodiment of the present invention, the second heat treatment method includes: heating at 100-200° C. for 10-60 min in an air atmosphere.

[0009] According to an embodiment of the present invention, the mixed layer is formed by multi-source evaporation deposition, including: a first evaporation source is used to evaporate the pore-forming agent; a second evaporation source includes a plurality of sub-evaporation sources, and the plurality of sub-evaporation sources are used to evaporate different perovskite inorganic salts.

[0010] According to an embodiment of the present invention, the evaporation rate of the pore-forming agent is

[0011] According to an embodiment of the present invention, the second evaporation source includes three sub-evaporation sources, and the three sub-evaporation sources are used to evaporate lead iodide, cesium bromide and lead bromide respectively, and the evaporation rate of the lead iodide is The evaporation rate of cesium bromide is The evaporation rate of lead bromide is

[0012] According to an embodiment of the present invention, the evaporated thickness of the lead iodide is 200-300 nm.

[0013] According to an embodiment of the present invention, the perovskite organic layer satisfies at least one of the following conditions: the perovskite organic layer is formed by evaporation or solution method; and the thickness of the perovskite organic layer is 100 to 200 nm.

[0014] According to an embodiment of the present invention, the substrate comprises a bottom cell.

[0015] According to an embodiment of the present invention, the bottom cell comprises a crystalline silicon cell, and a surface of the crystalline silicon cell close to the first charge transport layer is a velvet surface.

[0016] In another aspect of the present invention, the present invention provides a solar cell, according to an embodiment of the present invention. The solar cell is prepared by the method described above. Thus, the solar cell has a better energy conversion efficiency. Those skilled in the art can understand that the solar cell has all the features and advantages of the method for preparing a solar cell described above, and no further elaboration is given here.

[0017] In another aspect of the present invention, the present invention provides an electric device. According to an embodiment of the present invention, the electric device includes the solar cell described above. Thus, the electric device has good power usage performance. Those skilled in the art can understand that the electric device has all the features and advantages of the solar cell described above, and no further elaboration is given here.

[0018] In another aspect of the present invention, the present invention provides a power generation device. According to an embodiment of the present invention, the power generation device includes the solar cell described above. Thus, the power generation device has good power generation efficiency. Those skilled in the art can understand that the power generation device has all the features and advantages of the solar cell described above, and no further elaboration is given here. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0020] Figure 1 is a schematic diagram of a process for preparing a solar cell in one embodiment of the present invention;

[0021] Figure 2 is a schematic diagram of preparing a perovskite light-absorbing layer in another embodiment of the present invention;

[0022] Figure 3 It is a schematic structural diagram of a solar cell in another embodiment of the present invention.

[0023] Reference numerals: substrate 10 ; first charge transport layer 21 ; mixed layer 31 ; perovskite organic layer 32 ; perovskite light absorbing layer 30 ; passivation layer 40 ; second charge transport layer 22 ; buffer layer 50 ; electrode 60 . DETAILED DESCRIPTION

[0024] The scheme of the present invention will be explained below in conjunction with the embodiments. It will be appreciated by those skilled in the art that the following embodiments are only used to illustrate the present invention and should not be considered as limiting the scope of the present invention. Where specific techniques or conditions are not indicated in the embodiments, the techniques or conditions described in the literature in this area or the product specifications are used. The reagents or instruments used are not indicated by the manufacturer and are all conventional products that can be obtained commercially.

[0025] The present invention is described below with reference to specific embodiments. It should be noted that these embodiments are merely illustrative and do not limit the present invention in any way.

[0026] In one aspect of the present invention, the present invention provides a method for preparing a solar cell. Figure 1 and Figure 2, a method for preparing a solar cell comprises:

[0027] S100 : forming a first charge transport layer 21 on one side of the substrate 10 .

[0028] According to some embodiments of the present invention, the solar cell prepared by the method may be a single-junction perovskite cell. In this case, the substrate 10 may be a transparent conductive glass serving as a transparent electrode of the solar cell.

[0029] According to other embodiments of the present invention, the solar cell prepared by the method can be a stacked cell containing a perovskite cell. In some embodiments, the substrate 10 includes a bottom cell, that is, the perovskite cell is used as the top cell of the stacked cell. In some embodiments, the bottom cell includes a crystalline silicon cell, and the surface of the crystalline silicon cell close to the first charge transport layer is a velvet surface. In this case, it is necessary to further prepare the structure of the perovskite cell such as the first charge transport layer, the perovskite light absorption layer, and the second charge transport layer on the velvet surface.

[0030] In some embodiments, there are no restrictions on the specific type and structure of the crystalline silicon cell. Those skilled in the art can flexibly select the crystalline silicon cell that can be used as the bottom cell in the stacked battery according to actual needs. For example, the crystalline silicon cell can be different types of crystalline silicon cells such as HJT crystalline silicon cells, PERC crystalline silicon cells, and TOPCon crystalline silicon cells.

[0031] According to some embodiments of the invention, the first charge transport layer may be a hole transport layer, and thus the second charge transport layer subsequently formed is an electron transport layer; according to some embodiments of the invention, the first charge transport layer is an electron transport layer, and thus the second charge transport layer subsequently formed is a hole transport layer.

[0032] In some embodiments of the present invention, the hole transport layer can be a hole transport layer of a self-assembled monolayer, and its materials include [4-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphonic acid (MeO-4PACz), (4-(3,6-dimethyl-9H-carbazole-9-yl)butyl)phosphonic acid (Me-4PACz), [4-(9H-carbazole-9-yl)butyl]phosphonic acid (4PACz), (4-(3,6-dibromo-9H-carbazole-9-yl)butyl)phosphonic acid (4PACz), At least one of (2-(3,6-dimethyl-9H-carbazole-9-yl)ethyl)phosphonic acid (Br-4PACz), [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid (MeO-2PACz), (2-(3,6-dimethyl-9H-carbazole-9-yl)ethyl)phosphonic acid (Me-2PACz), (2-(9H-carbazole-9-yl)ethyl)phosphonic acid (2PACz), and (2-(3,6-dibromo-9H-carbazole-9-yl)ethyl)phosphonic acid (Br-2PACz). In some embodiments, the hole transport layer of the self-assembled monolayer can be obtained by evaporation or solution method. In the evaporation method, the evaporation rate is The thickness is 20-50nm; in the solution method, the concentration of the hole transport material in the solution is 0.2-2mg / ml, and the solvent is ethanol or isopropanol. Furthermore, the specific method of the solution method can be spin coating, spraying, scraping, slit coating, inkjet printing, ultrasonic spraying and the like. When spin coating is adopted, the spin coating rate is 2000-6000rpm.

[0033] In some other embodiments of the present invention, the hole transport layer may also be a non-self-assembled hole transport layer, and its material may include nickel oxide (NiO x, 1≤x≤2), cuprous iodide (CuI), cuprous oxide (Cu2O), cuprous thiocyanate (CuSCN), 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene (Spiro-OMeTAD), 2,2',7,7'-tetrakis(di-p-tolylamino)spiro-9,9'-bifluorene (Spiro-TTB), poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), and [4-(3,6-dimethoxy-9H-carbazole-9-yl)butyl]phosphonic acid (MeO-4PACz), (4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid (MeO-4PACz), One or more of [4-(9H-carbazole-9-yl)butyl]phosphonic acid (Me-4PACz), [4-(9H-carbazole-9-yl)butyl]phosphonic acid (4PACz), (4-(3,6-dibromo-9H-carbazole-9-yl)butyl)phosphonic acid (Br-4PACz), [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid (MeO-2PACz), (2-(3,6-dimethyl-9H-carbazole-9-yl)ethyl)phosphonic acid (Me-2PACz), (2-(9H-carbazole-9-yl)ethyl)phosphonic acid (2PACz), (2-(3,6-dibromo-9H-carbazole-9-yl)ethyl)phosphonic acid (Br-2PACz), etc. In some embodiments, the hole transport layer can be prepared by magnetron sputtering, atomic deposition, spin coating, etc.

[0034] According to other embodiments of the present invention, the electron transport layer includes but is not limited to tin oxide, fullerene and its derivatives, imide compounds, quinone compounds, etc. Exemplarily, the imide compounds include at least one of phthalimide, succinimide, N-bromosuccinimide, glutarimide or maleimide; Exemplarily, the quinone compounds include at least one of benzoquinone, naphthoquinone, phenanthrenequinone or anthraquinone; Exemplarily, fullerene and its derivatives include fullerene C 60 , Fullerene C 70 、PCBM([6,6]-phenyl-C 61 -methyl butyrate), [6,6]-phenyl C 71 Methyl butyrate (PC 71 BM).

[0035] S200 : forming a mixed layer 31 by evaporation on a side of the first charge transport layer 21 away from the substrate 10 , wherein the mixed layer 31 includes a perovskite inorganic salt and a pore-forming agent.

[0036] According to some embodiments of the present invention, the pore former includes an organic amine compound. In some embodiments, the pore former includes at least one of semicarbazide, allyl urea, tetramethyl urea or n-butyl urea. The above-mentioned materials can be decomposed into gas and removed at a relatively low temperature in a vacuum environment, forming holes in the perovskite inorganic layer (the layer structure corresponding to the mixed layer removing the pore former); and the above-mentioned organic amine compounds do not react with the perovskite inorganic salt, which is beneficial to ensure the stability of the perovskite inorganic salt; in addition, the pore former is co-evaporated with the perovskite inorganic salt, so that the pore former is uniformly dispersed in the perovskite inorganic salt, which can help to delay the reaction between the perovskite inorganic salts, and thus can effectively improve the subsequent reaction efficiency of the perovskite inorganic salt and the perovskite organic salt.

[0037] According to some embodiments of the present invention, a mixed layer is formed by multi-source evaporation deposition, that is, a plurality of evaporation sources are used to simultaneously evaporate different materials to form a mixed layer. In some embodiments, a first evaporation source and a second evaporation source are included, wherein the first evaporation source is used to evaporate a pore-forming agent; the second evaporation source includes a plurality of sub-evaporation sources, and the plurality of sub-evaporation sources are used to evaporate different perovskite inorganic salts. In this way, a plurality of different perovskite inorganic salts are co-evaporated with the pore-forming agent, which is conducive to the uniform distribution of the perovskite inorganic salt and the pore-forming agent, and can help to delay the reaction between the perovskite inorganic salt, thereby effectively improving the subsequent reaction efficiency of the perovskite inorganic salt and the perovskite organic salt.

[0038] According to some embodiments of the present invention, there are no special requirements for the specific type and quantity of the perovskite inorganic salt, and those skilled in the art can flexibly select it according to the existing materials of the perovskite light-absorbing layer. For example, the perovskite inorganic salt includes but is not limited to inorganic salts such as lead iodide, lead bromide, lead chloride, cesium iodide, cesium bromide, and cesium chloride.

[0039] According to some embodiments of the present invention, the second evaporation source includes three sub-evaporation sources, which are used to evaporate lead iodide, cesium bromide and lead bromide respectively. The evaporation rate of lead iodide is (For example, etc.), the evaporation rate of cesium bromide is (For example, etc.), the evaporation rate of lead bromide is (For example, wait).

[0040] Furthermore, in some embodiments, the evaporation rate of the pore-forming agent is (For example, In this way, the pore-forming agent of the above-mentioned evaporation rate has an appropriate proportion content in the mixed layer, which is helpful to form appropriate holes; if the evaporation rate of the pore-forming agent is low, the content of the pore-forming agent in the mixed layer is relatively low, so that fewer holes are generated, the increase of the reaction area of ​​the perovskite organic salt and the perovskite inorganic salt is not obvious, and then the improvement of the reaction efficiency between the perovskite organic salt and the perovskite inorganic salt is not obvious; if the evaporation rate of the pore-forming agent is high, the content of the pore-forming agent in the mixed layer is relatively high, which will relatively affect the reaction of the perovskite inorganic salt and the uniformity of the surface film formation, resulting in a serious decrease in the quality of the perovskite light-absorbing layer formed by the final reaction, and it may be unfavorable to completely remove the pore-forming agent, which is easy to cause the pore-forming agent to remain in the perovskite light-absorbing layer, reduce the quality of the perovskite light-absorbing layer, and thus affect the photoelectric conversion efficiency of the perovskite light-absorbing layer.

[0041] Further, according to some embodiments of the present invention, the evaporated thickness of lead iodide is 200-300 nm, such as 200 nm, 210 nm, 220 nm, 230 nm, 240 nm, 250 nm, 260 nm, 270 nm, 280 nm, 290 nm, 300 nm, etc. This is conducive to the full reaction of the perovskite inorganic salt and the organic salt, and a perovskite light-absorbing layer of suitable thickness is obtained.

[0042] S300 : forming a perovskite organic layer 32 on a surface of the mixed layer 31 away from the substrate 10 , wherein the perovskite organic layer 32 includes a perovskite organic salt.

[0043] According to some embodiments of the present invention, the perovskite organic salt may be at least one of formamidine iodide (FAI), formamidine bromide (FABr), and formamidine chloride (FACl).

[0044] According to some embodiments of the present invention, the perovskite organic salt can be prepared by evaporation or solution method. In some embodiments, the perovskite organic layer is prepared by evaporation, and the evaporation rate of the perovskite organic salt is (For example, In other embodiments, the perovskite organic layer is prepared by a solution method, wherein the perovskite organic salt is dissolved in a solvent to obtain a perovskite organic salt solution of a certain concentration, and then the perovskite organic salt solution is coated or spin-coated on the surface of the mixed layer, and the perovskite organic layer is obtained after drying and curing.

[0045] In some embodiments, the thickness of the perovskite organic layer is 100-200 nm, such as 100 nm, 110 nm, 120 nm, 130 nm, 140 nm, 150 nm, 160 nm, 170 nm, 180 nm, 190 nm, 200 nm, etc. This is conducive to the full reaction of the perovskite inorganic salt and the organic salt, and a perovskite light-absorbing layer of suitable thickness is obtained.

[0046] S400: performing a first heat treatment on the mixed layer 31 and the perovskite organic layer 32 to remove the pore-forming agent.

[0047] According to some embodiments of the present invention, the first heat treatment method includes: heating at 60 to 100° C. (for example, the heat treatment temperature is 60° C., 65° C., 70° C., 75° C., 80° C., 85° C., 90° C., 95° C., 100° C., etc.) for 30 to 60 min (for example, 30 min, 35 min, 40 min, 45 min, 50 min, 55 min, 60 min, etc.) in a vacuum environment, and the vacuum value is less than or equal to 3×10 -4 Pa. Under the above conditions, the organic amine compound pore former can be decomposed to generate gas escape, thereby generating holes, and the above temperature is relatively low, which will not cause the perovskite inorganic salt and the perovskite organic salt to decompose or cause adverse side reactions.

[0048] S500 : performing a second heat treatment on the mixed layer 31 and the perovskite organic layer 32 , and the perovskite inorganic salt and the perovskite organic salt react to obtain the perovskite light absorbing layer 30 .

[0049] According to some embodiments of the present invention, the second heat treatment method includes: heating at 100-200°C (for example, the heat treatment temperature is 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, 180°C, 190°C, 200°C, etc.) in an air atmosphere for 10-60 minutes (for example, 10 minutes, 20 minutes, 30 minutes, 35 minutes, 40 minutes, 45 minutes, 50 minutes, 55 minutes, 60 minutes, etc.). Under the above conditions, the reaction of the perovskite inorganic salt and the perovskite organic salt can be effectively promoted. The presence of the pores can provide sufficient reaction areas for the reaction of the perovskite inorganic salt and the perovskite organic salt, promote the full reaction of the perovskite inorganic salt and the perovskite organic salt, and obtain a perovskite light-absorbing layer with good performance.

[0050] According to some embodiments of the present invention, referring to Figure 3 , the method for preparing a solar cell further comprises:

[0051] S600 : forming a passivation layer 40 on a side of the perovskite light absorbing layer 30 away from the substrate 10 .

[0052] According to some embodiments of the present invention, the material of the passivation layer includes at least one of 2-thiopheneethylamine hydrochloride (TEACl), 1,4-phenylenediamine hydroiodide (PDADI), and phenylethylamine iodide (PEAI).

[0053] According to some embodiments of the present invention, the passivation layer can be prepared by evaporation deposition. In some embodiments, the evaporation rate of the passivation layer material is According to some other embodiments of the present invention, the passivation layer may be prepared by a solution method (such as coating or spin coating).

[0054] According to some embodiments of the present invention, the thickness of the passivation layer is 5-30 nm, such as 5 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, etc.

[0055] S700 : forming a second charge transport layer 22 on a side of the passivation layer 40 away from the substrate 10 .

[0056] According to some embodiments of the present invention, the above-mentioned first charge transport layer is a hole transport layer, and the second charge transport layer is an electron transport layer; according to some embodiments of the present invention, the above-mentioned first charge transport layer is an electron transport layer, and the second charge transport layer is a hole transport layer.

[0057] In some embodiments, the second charge transport layer can be prepared by magnetron sputtering, atomic deposition, spin coating, etc.

[0058] S800 : forming a buffer layer 50 on a side of the second charge transport layer 22 away from the substrate 10 .

[0059] According to some embodiments of the present invention, the material of the buffer layer is at least one of bathocuproine (BCP) or tin dioxide (SnO2).

[0060] According to some embodiments of the present invention, the buffer layer can be prepared by coating, spin coating, atomic layer deposition or other methods.

[0061] S900 : forming an electrode 60 on a side of the buffer layer 50 away from the substrate 10 .

[0062] According to some embodiments of the present invention, the electrode may be a metal electrode, such as a silver electrode or a copper electrode.

[0063] According to an embodiment of the present invention, during the preparation process, a pore former is mixed into the evaporated perovskite inorganic salt, and the pore former is removed in the first heat treatment, thereby forming pores in the perovskite inorganic layer. During the second heat treatment, the pores can increase the reaction area of ​​the perovskite organic salt and the perovskite inorganic salt, or in other words, increase the reaction space, thereby improving the reaction efficiency between the perovskite organic salt and the perovskite inorganic salt, and improving the sufficiency of the reaction between the solid phases, thereby helping to improve the energy conversion efficiency of solar cells.

[0064] In another aspect of the present invention, the present invention provides a solar cell, according to an embodiment of the present invention. The solar cell is prepared by the method described above. Thus, the solar cell has a better energy conversion efficiency. Those skilled in the art can understand that the solar cell has all the features and advantages of the method for preparing a solar cell described above, and no further elaboration is given here.

[0065] In another aspect of the present invention, the present invention provides an electric device. According to an embodiment of the present invention, the electric device includes the solar cell described above. Thus, the electric device has good power usage performance. Those skilled in the art can understand that the electric device has all the features and advantages of the solar cell described above, and no further elaboration is given here.

[0066] According to some embodiments of the present application, electrical devices may include mobile devices (such as mobile phones, laptops, etc.), electric vehicles (such as pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, etc.), electric trains, ships and satellites, energy storage systems, etc., but are not limited thereto.

[0067] In another aspect of the present invention, the present invention provides a power generation device. According to an embodiment of the present invention, the power generation device includes the solar cell described above. Thus, the power generation device has good power generation efficiency. Those skilled in the art can understand that the power generation device has all the features and advantages of the solar cell described above, and no further elaboration is given here.

[0068] In some embodiments, the power generation device can be used in ground power stations, aviation, construction, wearable power generation devices and other fields.

[0069] Example

[0070] Example 1

[0071] (1) The self-assembled monomolecular material 2PACz was spin-coated on one side of the HJT silicon bottom cell with ITO by spin coating. The concentration of 2PACz was 0.2 mg / ml, the solvent was ethanol, and the spin coating speed was 4000 rpm.

[0072] (2) Using an evaporation method, a mixed layer is deposited on the surface coated with the self-assembled hole transport layer. The material of the mixed layer is composed of PbI2, CsBr, PbBr2 and aminourea. The evaporation rate of PbI2 is The evaporation rate of CsBr is The evaporation rate of PbBr2 is The evaporation rate of semicarbazide is The evaporation was stopped when the PbI2 evaporation thickness reached 300 nm.

[0073] (3) The perovskite organic salt FAI is deposited on the surface of the mixed layer by evaporation. The evaporation rate of FAI is The evaporated thickness of the perovskite organic layer is 200 nm.

[0074] (4) The substrate obtained in step (3) was placed in a vacuum chamber and heated at 100°C for 30 min, and then the substrate was placed in air and heated at 150°C for 30 min to obtain a perovskite light absorbing layer FA 0.85 Cs 0.15 Pb(I 0.75 Br 0.25 )3.

[0075] (5) The passivation layer material PDADI is deposited on the surface of the perovskite light absorbing layer by evaporation method. The evaporation rate of PDADI is The thickness of the passivation layer is 5 nm.

[0076] (6) Using an evaporation method, a 20 nm thick electron transport layer C60, a 5 nm thick buffer layer BCP and a 200 nm thick metal electrode Ag are sequentially deposited on the surface of the passivation layer to obtain a solar cell.

[0077] Example 2

[0078] The steps for preparing the solar cell are basically the same as those in Example 1, except that the evaporation rate of semicarbazide is

[0079] Example 3

[0080] The steps for preparing the solar cell are basically the same as those in Example 1, except that the evaporation rate of semicarbazide is

[0081] Example 4

[0082] The steps for preparing the solar cell are basically the same as those in Example 1, except that the evaporation rate of semicarbazide is

[0083] Example 5

[0084] The steps for preparing the solar cell are basically the same as those in Example 1, except that the evaporation rate of semicarbazide is

[0085] Comparative Example 1

[0086] The steps for preparing the solar cell are basically the same as those in Example 1, except that in step (2), a mixed layer is deposited on the surface coated with the self-assembled hole transport layer by evaporation, and the material of the mixed layer is composed of PbI2, CsBr and PbBr2, and the evaporation rate of PbI2 is The evaporation rate of CsBr is The evaporation rate of PbBr2 is The evaporation was stopped when the PbI2 evaporation thickness reached 300 nm.

[0087] The data of parameter changes in the above-mentioned embodiments 1 to 5 and comparative example 1 are shown in Table 1. The solar cells obtained in the above-mentioned embodiments 1 to 5 and comparative example 1 are subjected to performance tests, and the test data can be seen in Table 1 below. The test method is: the solar cell is placed under a standard sunlight intensity of AM1.5G, a source meter is used to electrically connect the battery, and a 10mV step voltage is used to scan in the range of 2V to -0.5V, and the current output by the solar cell at each voltage point is recorded, so as to obtain the power conversion efficiency PCE and the open circuit voltage V OC , short circuit current density J SC And fill factor FF, each optoelectronic parameter satisfies the formula: PCE = V OC ×J SC ×FF.

[0088] Table 1

[0089]

[0090] It can be seen from the data in Table 1 that as the evaporation rate of semicarbazide increases, the content of semicarbazide in the mixed layer gradually increases, and the energy conversion efficiency of the solar cell gradually increases first, and then gradually decreases. The energy conversion efficiency of solar cells reaches the best when the evaporation rate of aminourea is appropriate. It can be seen that when the evaporation rate of aminourea is appropriate, the conversion efficiency of solar cells can be greatly improved. If the content of aminourea is too much, it will be detrimental to the improvement of the performance of solar cells.

[0091] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0092] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0093] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A method for preparing a solar cell, characterized in that: include: forming a first charge transport layer on one side of the substrate; Forming a mixed layer by evaporating on a side of the first charge transport layer away from the substrate, wherein the mixed layer includes a perovskite inorganic salt and a pore-forming agent; forming a perovskite organic layer on a surface of the mixed layer away from the substrate, wherein the perovskite organic layer comprises the perovskite organic salt; Performing a first heat treatment on the mixed layer and the perovskite organic layer to remove the pore former; The mixed layer and the perovskite organic layer are subjected to a second heat treatment, and the perovskite inorganic salt and the perovskite organic salt react to obtain a perovskite light-absorbing layer.

2. The method according to claim 1, characterized in that The pore former includes an organic amine compound.

3. The method according to claim 2, characterized in that The pore former includes at least one of semicarbazide, allyl urea, tetramethyl urea or n-butyl urea.

4. The method according to claim 2 or 3, characterized in that: The first heat treatment method comprises: heating at 60-100°C for 30-60 minutes in a vacuum environment, with a vacuum value of less than or equal to 3×10 -4 Pa.

5. The method according to any one of claims 1 to 3, characterized in that: The second heat treatment method includes: heating at 100-200° C. for 10-60 minutes in an air atmosphere.

6. The method according to any one of claims 1 to 3, characterized in that: The mixed layer is formed by multi-source evaporation deposition, including: a first evaporation source is used to evaporate the pore-forming agent; a second evaporation source includes a plurality of sub-evaporation sources, and the plurality of sub-evaporation sources are used to evaporate different perovskite inorganic salts.

7. The method according to claim 6, characterized in that The evaporation rate of the pore former 8. The method according to claim 7, characterized in that The second evaporation source includes three sub-evaporation sources, and the three sub-evaporation sources are used to evaporate lead iodide, cesium bromide and lead bromide respectively. The evaporation rate of the lead iodide is The evaporation rate of cesium bromide is The evaporation rate of lead bromide is 9. The method according to claim 8, characterized in that The evaporated thickness of the lead iodide is 200-300nm.

10. The method according to any one of claims 1 to 3, characterized in that: The perovskite organic layer satisfies at least one of the following conditions: The perovskite organic layer is formed by evaporation or solution method; The thickness of the perovskite organic layer is 100-200 nm.

11. The method according to any one of claims 1 to 3, characterized in that: The substrate includes a bottom cell.

12. The method according to claim 11, characterized in that The bottom cell comprises a crystalline silicon cell, and a surface of the crystalline silicon cell close to the first charge transport layer is a velvet surface.

13. A solar cell, characterized in that: It is prepared by the method described in any one of claims 1 to 12.

14. An electrical device, characterized in that: The electrical device comprises the solar cell according to claim 13.

15. A power generation device, characterized in that: The power generation device comprises the solar cell according to claim 13.

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